I would look for a replacement base first. Maybe try to contact the manufacturer?
Second, i know many here will scoff at this, but... My chinesium special has been great. I've beat the hell out of it and it continues to work flawlessly. Two axis-rotate, and pipe clamp.
Or you could spend a ton more on an old used beat-up vise, and then spend hours/days/weeks rebuilding and painting it. Which would cost you quite a bit more. But I actually use my tools to repair other things, not just to repair...other tools, so I don't have time for that.
You could try here:
http://jerseydiscounttoolco.com/store#!/Wilton/c/20343091/offset=0&sort=nameAsc
The owner, nick, has a great online reputation. He runs a gearwrench truck, and sells everything the other tool truck don't sell. On the link I posted he's selling a nice Wilton and hammer combo, a lot of guys have been happy with it.
of course I see it much cheaper here too:
https://www.amazon.com/dp/B00WH6JIEO/?tag=atomicindus08-20